JPH11115789A - Motor-driven power steering control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate sudden(or dull) variation of steering torque at starting of a control device and the like and favorably stabilize steering feeling at beginning of motor control by beginning energization by a motor after the steering torque detected by a steering torque detecting means becomes lower than a fixed value. SOLUTION: The condition of a Flag 1 judging allowing/prohibiting of beginning of motor control is judged (P5). When the condition of the Flag 1 is clear, the motor control is prohibited, and when it is set, the motor control is allowed. At Clear, steering torque input at P4 is judged whether it is over A or not for example (P6). This A is, for example, set to be the threshold value of a deadband without motor assist. When steering torque is less than A, the Flag 1 is set (P7), to return to P1. Set of the Flag 1 is judged (P5), and it is jumped to motor control to begin the motor control (P10). When the steering torque is over A, the Flag 1 is again cleared (P8) to jump to P4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control at the time of starting of a control device, and more particularly to an electric power steering control device for assisting steering operation.

[0002]

2. Description of the Related Art A generally known electric power steering control device for assisting steering steering detects a steering torque of a steering system, generates an assist torque for a motor based on the detected signal, and controls the motor for steering. We are trying to reduce it. For example, FIG. 13 is a diagram illustrating a system configuration of an electric power steering control device. In the figure, reference numeral 9 denotes a steering wheel which receives a steering torque of the driver;
Is a torque sensor connected to the steering wheel 9 via the first steering shaft 10a, and outputs an electric signal to the control unit 3 to be described later according to the rotational force applied to the steering wheel 9. Reference numeral 12 denotes a worm wheel connected to the torque sensor 4 via a second steering shaft 10b, 13a denotes a first universal joint connected to the worm wheel 12 via a third steering shaft 10c, and 13b denotes a fourth universal joint. First universal joint 13a via steering shaft 10d
, A pinion gear shaft mechanically connected to the second universal joint 13b, 15 is a rack shaft having a rack tooth portion 15a that meshes with the pinion gear shaft 14, and 16a is a rack shaft 15. A pole joint connecting one end to one tie rod 17a; a pole joint 16b connecting the other end of the rack shaft 15 to the other tie rod 17b;
Reference numeral 3 denotes a control unit for driving and controlling the motor 5;
Is a battery for supplying a power supply voltage to the control unit 3 and the motor 5 through the key switch 2.
1, a clutch for controlling mechanical coupling and disengagement between 1; 7, an engine rotation sensor for detecting the rotation of the engine and outputting an electric signal corresponding to the engine speed to the control unit 3; Is a vehicle speed sensor that outputs an electric signal corresponding to the vehicle speed to the control unit 3. The worm shaft 11 meshes with the worm wheel 12.

In the conventional electric power steering control device configured as described above, when the key switch 2 of the vehicle is turned on, the control unit 3 is started immediately,
For example, if the key switch 2 is turned on in a state where the steering wheel 9 is gripped and steering torque is applied to start the control, the motor 5 that has been stopped is started, and the applied steering force is suddenly reduced. Such a sudden decrease in the steering force has a problem that the starting feeling is deteriorated.

Therefore, as described in Japanese Patent Publication No. 7-94226, the control signal of the motor 5 is increased by gradually increasing the torque of the motor 5 to a required torque when the control unit 3 is started. A device for performing correction control has been proposed.

[0005]

The gradual increase of the torque of the motor 5 as in the conventional apparatus clearly reduces the steering force applied by the driver, though gradually. However, if the key switch 2 is turned on while the steering wheel 9 is kept turned, the steering torque gradually changes against the driver's will, which causes deterioration of the steering feeling. Also, depending on the speed of the gradual increase, there is a problem that the response of the steering force becomes small, the vehicle tends to be over-assisted, and the steering wheel may be turned too much.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and there is no abrupt (or slow) fluctuation of the steering torque at the time of starting the control device, and the like. It is an object of the present invention to provide an electric power steering device capable of stabilizing a steering feeling.

[0007]

According to a first aspect of the present invention, there is provided an electric power steering control device, comprising: a steering torque detecting means for detecting a steering torque of a steering system; a motor connected to the steering system for energizing the torque; Motor control means for starting energization by the motor after the steering torque detected by the steering torque detection means becomes equal to or less than a predetermined value.

According to a second aspect of the present invention, there is provided an electric power steering control device, comprising: a steering torque detecting means for detecting a steering torque of a steering system; a motor connected to the steering system for energizing the torque; and a steering system and the motor. A clutch to be connected or disconnected, a clutch control means for controlling the clutch, and after the operation of the clutch control means is detected, the energization by the motor is started after the steering torque detected by the torque detection means becomes a predetermined value or less. And a motor control means.

According to a third aspect of the present invention, in the electric power steering control device, the motor control means outputs the clutch connection drive signal by the clutch control means, and the steering torque detected by the steering torque detection means becomes a predetermined value or less. After that, the urging by the motor is started.

According to a fourth aspect of the present invention, there is provided an electric power steering control apparatus, comprising: a steering torque detecting means for detecting a steering torque of a steering system; a motor connected to the steering system for energizing the torque; and a steering system and the motor. A clutch to be connected or disconnected, a clutch control unit to control the clutch, a clutch state detection unit to detect a connection state of the clutch, and detection by the steering torque detection unit after the clutch state detection unit determines connection of the clutch. Motor control means for starting the energization by the motor after the steering torque falls below a predetermined value.

According to a fifth aspect of the present invention, there is provided an electric power steering control apparatus, comprising: a steering torque detecting means for detecting a steering torque of a steering system; a motor connected to the steering system for energizing the torque; And a motor control means for starting the energization by the motor after the steering torque detected by the steering torque detection means becomes equal to or less than a predetermined value after the power-on detection by the power-on detection means. Things.

According to a sixth aspect of the present invention, there is provided an electric power steering control device, comprising: a steering torque detecting means for detecting a steering torque of a steering system; a motor connected to the steering system for energizing the torque; Voltage value detecting means for detecting whether the voltage has reached a predetermined value or more, and detecting that the power supply voltage has reached a predetermined value or more,
Motor control means for starting energization by the motor after the steering torque detected by the steering torque detection means becomes equal to or less than a predetermined value.

According to a seventh aspect of the present invention, there is provided an electric power steering control apparatus, comprising: a steering torque detecting means for detecting a steering torque of a steering system; a motor connected to the steering system for energizing the torque; The engine control apparatus includes: a start determination unit; and a motor control unit that starts energization by the motor after a steering torque detected by the steering torque detection unit becomes equal to or less than a predetermined value after the engine start determination by the engine start determination unit. is there.

According to an eighth aspect of the present invention, there is provided an electric power steering control device, comprising: a steering torque detecting means for detecting a steering torque of a steering system; a motor connected to the steering system for energizing the torque; A motor control suspending means for suspending, and when the motor control is resumed after the motor control is suspended by the motor control suspending means, the energization by the motor is started after the steering torque detected by the steering torque detecting means becomes a predetermined value or less. And a motor control means.

According to a ninth aspect of the present invention, in the electric power steering control device, the motor control stopping means is configured to stop the motor control and control the motor based on a comparison between the engine speed input from the engine rotation sensor and the vehicle speed input from the vehicle speed sensor. This is to determine resumption.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Next, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of the electric power steering control device according to the present embodiment. In the drawing, the same reference numerals as those in FIG. 13 indicate the same or corresponding parts. In the figure, 1
Is a battery, 2 is a key switch, 3A is a control unit according to the present embodiment, 4 is a torque sensor, and 5 is a motor.

The internal structure of the control unit 3A is as follows.
A power supply circuit 31 connected to the battery 1 by the key switch 2 and supplied with a power supply voltage of the battery 1 when the key switch 2 is turned on, and an input I connected to the torque sensor 4
/ F circuit 32, a power supply circuit 31, a microcomputer 33 that calculates an output to the motor 5 based on a signal from the input I / F circuit 32, and a motor drive circuit 34 that drives the motor 5 based on an output signal from the microcomputer 33. Be composed.

Since the power supply circuit 31 supplies the internal power supply of the control unit 3A, when the key switch 2 is in the off state, no power supply is supplied to the control unit 3A.

FIG. 2 is a flowchart for explaining the operation of the present embodiment. Hereinafter, the operation of the present embodiment will be described with reference to the flowchart of FIG. P0 indicates a starting point of the present process. At P1, the state of the key switch 2 is detected. Then, on / off determination of the key switch 2 is performed at P2. As described above, since the power supply to the control unit 3A is determined when the key switch 2 is on / off, the power is not supplied when the key switch 2 is off.
Return to P1.

When the key switch 2 is determined to be on, power is supplied to the control unit 3A.
First, control data and the like are initialized in P3. At this time, Flag1 described later is cleared.

At P4, the output signal of the torque sensor 4 is input via the input I / F circuit 32. Then, in P5, the state of Flag1 for judging permission / prohibition of the start of motor control is determined. If the state of Flag1 is Clear, motor control is prohibited, and if Set, motor control is permitted.
When Flag1 is set, the process jumps to P10 to start motor control.

At the time of Clear, it is determined whether the steering torque input at P4 is, for example, A or more. This A is, for example, a threshold value of a dead zone where no motor assist is performed. When the steering torque is less than A, Flag1 is set at P7 and P1 is set.
Return to 4. Then, Set of Flag1 is determined in P5, and the process jumps to the motor control of P10 to start the motor control. When the steering torque is equal to or larger than A, the flag 1 is cleared again at P8, and the control jumps to P4.

Then, the steering torque is input again at P4,
At P6, it is determined whether the steering torque is less than A. As described above, after the key switch 2 is turned on, that is, when the motor control is started from the motor control stopped state after the power supply voltage is turned on, the motor control is not started unless the steering torque becomes less than A.

Embodiment 2 FIG. In the present embodiment, after the connection drive signal is output to the clutch that connects or disconnects the steering system and the motor, the energization by the motor is started after the steering torque detected by the steering torque detection unit becomes a predetermined value or less. . Next, the operation of the electric power steering control device according to Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 3 is a configuration diagram of the electric power steering control device according to the present embodiment. In the drawing, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts. In the drawing, reference numeral 6 denotes a clutch for mechanically connecting / disconnecting the motor 5 and the steering system, and 3B denotes a controller according to the present embodiment.
A clutch drive circuit for driving clutch 6 is included in addition to the configuration of controller 3A according to the first embodiment.

The operation of this embodiment will be described below with reference to the flowchart of FIG. Note that the same reference numerals as those used in the flowchart shown in FIG. 2 perform the same processing, and a description thereof will be omitted. After reading the steering torque signal in P4, clutch control is performed in P20. In the clutch control, for example, the microcomputer 33 outputs a clutch-on command signal to the clutch drive circuit 35 when the key switch 2 is turned on, and outputs a clutch-off command signal when the key switch 2 is turned off.

After the Clear determination of Flag1 at P5, the output state of the command signal to the clutch drive circuit 35 is determined at P21.
Jump to Flag1Clear processing. If a clutch-on command signal is output, the level of the steering torque is determined at P6. As described above, the motor control after the clutch-on command signal is output to the clutch drive circuit 35 does not start the motor control unless the steering torque becomes less than A. If there is no command signal to turn on the clutch, the motor control is not started.

Embodiment 3 In the second embodiment, the motor control is started based on the steering torque value and the signal output state to the clutch drive circuit 35. However, in the present embodiment, the clutch drive is performed instead of the output state of the command signal to the clutch drive circuit 35. The output state of the actual clutch ON / OFF drive signal from the circuit 35 is determined.

Next, the operation of the electric power steering control device according to Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 5 is a configuration diagram of the electric power steering control device according to the present embodiment. In the drawing, the same reference numerals as those in FIG. 3 indicate the same or corresponding parts. In the figure, reference numeral 3C denotes a controller according to the present embodiment. In addition to the configuration of the controller 3B according to the second embodiment, a clutch drive circuit 35
And a clutch state detecting circuit 36 for monitoring the output state of the motor. The clutch state detection circuit 36 detects whether or not the clutch drive circuit 35 is outputting a clutch on / off drive signal in accordance with a clutch on / off command signal from the microcomputer 33.

The operation of this embodiment will be described below with reference to the flowchart of FIG. Note that the same reference numerals as those used in the flowchart shown in FIG. 4 perform the same processing, and a description thereof will be omitted. In FIG. 6, after the clutch is controlled at P20, the clutch drive circuit 35 outputs a clutch on / off drive signal in accordance with the clutch on / off command signal from the microcomputer 33 via the clutch state detection circuit 36 at P22. Or to detect.

After the flag 1 is judged to be clear in flag P5, the detection state of the clutch state detection circuit 36 is judged in step P23. If the clutch-off drive signal output is detected, the flow jumps to flag flag clear processing in step P8.
If the clutch-on drive signal output is detected, the level of the steering torque is determined at P6.

As described above, in the motor control start after judging the output state of the ON drive signal to the clutch 6, the motor control is not started unless the steering torque is less than A in P6. If the output of the clutch-on drive signal is not determined, the motor control is not started.

In this embodiment, an example of detecting the output state of the drive signal to the clutch 6 has been described.
The same effect can be obtained even if the driving state itself is detected.

Embodiment 4 FIG. In the present embodiment, the power supply circuit 3
The motor control process is started by the microcomputer 33 after the battery voltage applied to the microcomputer 1 reaches a predetermined level.

Next, the operation of the electric power steering control device according to Embodiment 4 of the present invention will be described with reference to the drawings. FIG. 7 is a configuration diagram of the electric power steering control device according to the present embodiment. In the drawing, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts. In the figure, reference numeral 3D denotes a controller according to the present embodiment. In addition to the configuration of the controller 3A according to the first embodiment, a power supply voltage for detecting the power supply voltage of the battery 1 connected to the power supply circuit via the key switch 2 A detection circuit 37 is included.

The operation of this embodiment will be described below with reference to the flowchart of FIG. Note that the same reference numerals as those used in the flowchart shown in FIG. 2 perform the same processing, and a description thereof will be omitted. In FIG. 8, after reading the steering torque signal at P4, the voltage of the battery 1 applied to the power supply circuit 31 via the power supply voltage detection circuit 37 is detected at P30.

Further, after the Clear determination of Flag1 in P5, the state of the power supply voltage detected by the power supply voltage detection circuit 37 is determined in P31.
Jump to ear processing. This B is, for example, the motor 1
Level enough to supply sufficient power to Also, B
If so, the level of the steering torque is determined in P6.

As described above, if the power supply voltage does not exceed a predetermined level, the motor control is not started. Further, the motor control does not start unless the steering torque becomes less than A after the power supply voltage becomes equal to or higher than the predetermined level.

Embodiment 5 In the present embodiment, motor control is not started unless the steering torque becomes less than A after the engine speed reaches or exceeds a predetermined level.

Next, the operation of the electric power steering control device according to Embodiment 5 of the present invention will be described with reference to the drawings. FIG. 9 is a configuration diagram of the electric power steering control device according to the present embodiment. In the drawing, the same reference numerals as those in FIG. 1 indicate the same or corresponding parts. In the figure, reference numeral 3E denotes a controller according to the present embodiment. In addition to the configuration of the controller 3A according to the first embodiment, an electric signal corresponding to the engine speed is sent from the engine speed sensor 7 for detecting the engine speed to the microcomputer 33. An input I / F circuit for inputting is included.

Hereinafter, the operation of this embodiment will be described with reference to the flowchart of FIG. Note that the same reference numerals as those used in the flowchart shown in FIG. 2 perform the same processing, and a description thereof will be omitted. In FIG. 10, after reading the steering torque signal at P4, an electric signal corresponding to the engine speed detected by the engine speed sensor 7 is input at P40 to the input I.
It is read into the microcomputer 33 via the / F circuit 38.

After the Clear determination of Flag1 in P5, the engine speed read in P40 is determined,
If it is less than the value, the process jumps to Clear processing of Flag 1 of P8. This C is, for example, the number of revolutions when the engine is idling. If it is not less than C, the level of the steering torque is determined at P6.

As described above, the motor control is not started unless the engine speed becomes equal to or more than the predetermined value and the engine start is determined. Further, if the steering torque does not become less than A after the engine rotation speed becomes equal to or higher than the predetermined level after the engine start is determined, the motor control is not started.

Embodiment 6 FIG. In this embodiment, a normal vehicle speed proportional to the engine speed is determined, and the steering torque is set to A.
The motor control is not started unless it becomes less than the predetermined value.

Next, the operation of the electric power steering control apparatus according to Embodiment 5 of the present invention will be described with reference to the drawings. FIG. 11 is a configuration diagram of the electric power steering control device according to the present embodiment. In the drawing, the same reference numerals as those in FIG. 9 indicate the same or corresponding parts. In the figure, reference numeral 3F denotes a controller according to the present embodiment. In addition to the configuration of the controller 3E according to the fifth embodiment, an electric signal corresponding to the engine speed is sent from the engine speed sensor 7 for detecting the engine speed to the microcomputer 33. Input I / F circuit 38 for input
And an input I / F circuit 39 for inputting an electric signal corresponding to the vehicle speed from the vehicle speed sensor 8 for detecting the vehicle speed to the microcomputer 33.

Hereinafter, the operation of this embodiment will be described with reference to the flowchart of FIG. Note that the same reference numerals as those used in the flowchart shown in FIG. 2 perform the same processing, and a description thereof will be omitted. In FIG. 12, after reading the steering torque signal at P4, an electric signal corresponding to the vehicle speed detected by the vehicle speed sensor 8 is read via the input I / F circuit 39 at P50.

Thereafter, in P40, an electric signal corresponding to the engine speed detected by the engine speed sensor 7 is input to the input I / F.
Read via the circuit 38. P51 compares, for example, the engine speed read at P40 with the vehicle speed read at P50. If the vehicle speed when the engine is rotating at high speed is zero, it is determined that the vehicle speed is abnormal and that the vehicle speed sensor 8 or the power transmission mechanism has failed. I do.

However, if the vehicle speed is detected at P50, it is determined that the vehicle is normal. Then, in P52, the presence or absence of the failure determination in P51 is determined. If there is a failure determination (abnormal), P53
To turn off the motor, and clear the flag Flag2 that is cleared when it is determined that there is an abnormality in P54. Then, P53, P54 until the vehicle speed is determined to be normal in P51.
Is repeated to determine whether the abnormality is transient.

After determining in P52 that there is no abnormality, the program proceeds to P55.
To determine the Flag2 state. If there is a history of detecting the presence of abnormality, Flag2 is cleared,
If ag2 is Clear, it is determined at P56 whether the steering force is A or more. If it is equal to or larger than A, Flag2 is cleared and the program jumps to P4. If it is less than A, Flag2 is set in P57, and the program jumps to P4. Flag2 is S in P55
If it is set, jump to P10 to perform motor control.

As described above, after the motor output is stopped due to the failure determination, the motor control is not restarted unless the steering torque becomes less than A even if the normal state is detected. Further, in the present embodiment, the example in which the motor output is stopped due to the abnormality of the vehicle speed sensor is described. However, the same processing can be performed under all the failure conditions in which the motor control is restarted by canceling the failure determination condition.

[0050]

According to the first aspect of the present invention, the steering torque detecting means for detecting the steering torque of the steering system, the motor connected to the steering system for energizing the torque, and the steering detected by the steering torque detecting means. A motor control means for starting the energization by the motor after the torque has become equal to or less than a predetermined value. Moreover, there is an effect that a stable electric power steering apparatus having a good steering feeling at the start of motor control can be supplied.

According to the second aspect of the present invention, a steering torque detecting means for detecting a steering torque of the steering system, a motor connected to the steering system for energizing the torque, and a clutch for connecting or disconnecting the steering system and the motor. And clutch control means for controlling the clutch, and motor control means for starting energization by the motor after the steering torque detected by the torque detection means becomes equal to or less than a predetermined value after detecting the operation of the clutch control means. With this arrangement, an uncomfortable feeling due to a sudden (or slow) change in the steering torque at the start of the motor control after the clutch connection output can be eliminated, and a stable electric power steering apparatus with a good starting feeling can be obtained. effective.

According to the third aspect of the present invention, after the clutch control means outputs the clutch connection drive signal, the motor control means operates the motor after the steering torque detected by the steering torque detection means becomes a predetermined value or less. By starting the energization, an uncomfortable feeling due to a sudden (or slow) fluctuation of the steering torque at the start of the motor control after the clutch connection output is determined is eliminated, and the electric power steering apparatus has a good starting feeling and a stable feeling. There is an effect that can be obtained.

According to the fourth aspect of the present invention, a steering torque detecting means for detecting a steering torque of the steering system, a motor connected to the steering system for energizing the torque, and a clutch for connecting or disconnecting the steering system and the motor. A clutch control unit that controls the clutch, a clutch state detection unit that detects a connection state of the clutch, and a steering torque detected by the steering torque detection unit after the clutch connection detection unit determines that the clutch is connected. The motor control means for starting the energization by the motor after the value becomes equal to or less than the value eliminates a sense of discomfort due to a sudden (or slow) change in the steering torque at the start of the motor control after the clutch connection is determined. An electric power steering device with good feeling and stability can be obtained. There is an effect. Further, since motor control is not performed due to clutch abnormality or the like, there is an effect that reliability regarding safety is improved.

According to the fifth aspect of the present invention, the steering torque detecting means for detecting the steering torque of the steering system, the motor connected to the steering system for energizing the torque, and the power-on detecting means for detecting the power-on of the device. And motor control means for starting the energization by the motor after the steering torque detected by the steering torque detection means after the power-on detection by the power-on detection means becomes a predetermined value or less,
The motor control means starts energizing by the motor after the steering torque detected by the steering torque detection means becomes less than or equal to a predetermined value after the power is turned on. Therefore, when the motor control is started after the power is turned on, the steering torque is rapidly (or slowly) increased. 3.) It is possible to eliminate the uncomfortable feeling due to the fluctuation and to obtain an electric power steering apparatus having a good starting feeling and a stable operation.

According to the present invention, the steering torque detecting means for detecting the steering torque of the steering system, the motor connected to the steering system for energizing the torque, and the power supply voltage exceeding a predetermined value after the power supply of the device is turned on. Voltage value detecting means for detecting whether or not the power supply voltage has reached a predetermined value or more, and when the steering torque detected by the steering torque detecting means has become a predetermined value or less, the motor Motor control means for starting energization, the motor control means controlling the motor after the steering torque detected by the steering torque detection means becomes equal to or less than a predetermined value after the power supply voltage detected after turning on the power becomes a predetermined value or more. To eliminate the discomfort caused by a sudden (or slow) change in the steering torque at the start of motor control after the power is turned on. There is an effect that it is possible to obtain an electric power steering device with stability good.

According to the present invention, the steering torque detecting means for detecting the steering torque of the steering system, the motor connected to the steering system for energizing the torque, the engine start determining means for determining the engine start, Motor control means for starting the energization by the motor after the steering torque detected by the steering torque detection means has become equal to or less than a predetermined value after the engine start determination by the engine start determination means; After the engine start is determined by the means, the energization by the motor is started after the steering torque detected by the steering torque detecting means becomes a predetermined value or less. Therefore, when the motor control is started after the engine start is determined, the steering torque suddenly (or slowly) increases. ) Electric power that eliminates discomfort caused by fluctuations and has good starting feeling and stability There is an effect that it is possible to obtain the bearings device.

According to the present invention, the steering torque detecting means for detecting the steering torque of the steering system, the motor connected to the steering system for energizing the torque, and the motor for judging the suspension of the control of the motor are provided. Control suspending means, and motor control means for starting energization by the motor after the steering torque detected by the steering torque detecting means becomes equal to or less than a predetermined value when the motor control is resumed after the motor control is suspended by the motor control suspending means. When the motor control means stops the motor control according to the determination result by the motor control stop means and restarts the motor control, the motor control means applies the bias by the motor after the steering torque detected by the steering torque detection means becomes a predetermined value or less. To eliminate the discomfort caused by a sudden (or slow) change in the steering torque when the motor control is restarted. Duck start feeling the effect can be obtained an electric power steering apparatus with a good stability.

According to the ninth aspect of the present invention, the motor control stopping means determines whether to stop the motor control and restart the motor control based on a comparison between the engine speed input from the engine rotation sensor and the vehicle speed input from the vehicle speed sensor. In addition, since motor control is not performed due to a sensor abnormality or the like, there is an effect that reliability regarding safety is also improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an electric power steering control device according to a first embodiment.

FIG. 2 is a flowchart illustrating an operation of the electric power steering control device according to the first embodiment.

FIG. 3 is a configuration diagram of an electric power steering control device according to a second embodiment.

FIG. 4 is a flowchart illustrating an operation of the electric power steering control device according to the second embodiment.

FIG. 5 is a configuration diagram of an electric power steering control device according to a third embodiment.

FIG. 6 is a flowchart illustrating an operation of the electric power steering control device according to the third embodiment.

FIG. 7 is a configuration diagram of an electric power steering control device according to a fourth embodiment.

FIG. 8 is a flowchart illustrating an operation of the electric power steering control device according to the fourth embodiment.

FIG. 9 is a configuration diagram of an electric power steering control device according to a fifth embodiment.

FIG. 10 is a flowchart illustrating an operation of the electric power steering control device according to the fifth embodiment.

FIG. 11 is a configuration diagram of an electric power steering control device according to a sixth embodiment.

FIG. 12 is a flowchart illustrating an operation of the electric power steering control device according to the sixth embodiment.

FIG. 13 is a configuration diagram showing a system of a conventional electric power steering control device.

[Explanation of symbols]

Reference Signs List 1 battery, 3A-3F controller, 4 torque sensor, 5 motor, 7 engine rotation sensor, 8 vehicle speed sensor, 31 power supply circuit, 34 motor drive circuit, 3
7 Power supply voltage detection circuit.

Continuation of the front page (51) Int.Cl. ⁶ Identification code FI B62D 127: 00 (72) Inventor Takuhiro Okagami 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Kifu Takayuki Takashi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Shigeki Otagaki 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation (72) Inventor Shunichi Wada Tokyo 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (9)

[Claims] 1. A steering torque detecting means for detecting a steering torque of a steering system, a motor connected to the steering system for energizing the torque, and after the steering torque detected by the steering torque detecting means becomes a predetermined value or less. An electric power steering control device, comprising: a motor control unit that starts energization by the motor. 2. A steering torque detecting means for detecting a steering torque of a steering system, a motor connected to the steering system for energizing the torque, a clutch for connecting or disconnecting the steering system and the motor, and controlling the clutch. A clutch control unit; and a motor control unit that starts energization by the motor after the steering torque detected by the torque detection unit becomes equal to or less than a predetermined value after the operation of the clutch control unit is detected. Electric power steering control device. 3. The motor control means starts the energization by the motor after the steering torque detected by the steering torque detection means becomes equal to or less than a predetermined value after a clutch connection drive signal is output by the clutch control means. The electric power steering control device according to claim 2, wherein: 4. A steering torque detecting means for detecting a steering torque of a steering system, a motor connected to the steering system for energizing the torque, a clutch for connecting or disconnecting the steering system and the motor, and controlling the clutch. A clutch control unit, a clutch state detection unit that detects a connection state of the clutch, and the steering torque detected by the steering torque detection unit after the clutch state detection unit determines that the clutch is connected to a predetermined value or less. An electric power steering control device comprising a motor control means for starting energization by a motor. 5. A steering torque detecting means for detecting a steering torque of a steering system, a motor connected to the steering system for energizing the torque, a power-on detecting means for detecting power-on of the device, and the power-on detecting means. And a motor control means for starting the energization by the motor after the steering torque detected by the steering torque detection means becomes equal to or less than a predetermined value after the power-on detection of the electric power steering control apparatus. 6. A steering torque detecting means for detecting a steering torque of a steering system, a motor connected to the steering system for energizing the torque, and detecting whether a power supply voltage has reached a predetermined value or more after power-on of the device. Voltage value detecting means,
Motor control means for detecting that the power supply voltage has reached a predetermined value or more and starting energization by the motor after the steering torque detected by the steering torque detection means has become a predetermined value or less. Characteristic electric power steering control device. 7. A steering torque detecting means for detecting a steering torque of a steering system, a motor connected to the steering system for energizing the torque, an engine start determining means for determining an engine start, and an engine based on the engine start determining means. An electric power steering control device, comprising: motor control means for starting energization by the motor after the steering torque detected by the steering torque detection means becomes equal to or less than a predetermined value after starting determination. 8. A steering torque detecting means for detecting a steering torque of a steering system, a motor connected to the steering system for energizing the torque, a motor control stopping means for temporarily stopping control of the motor, and a motor control stop Motor control means for starting energization by the motor when the steering torque detected by the steering torque detection means becomes equal to or less than a predetermined value when the motor control is stopped and the motor control restart is detected by the means. Electric power steering control device. 9. The motor control suspending means judges motor control suspension and motor control restart based on a comparison between an engine speed inputted from an engine revolution sensor and a vehicle speed inputted from a vehicle speed sensor. 9. The electric power steering control device according to 8.